Expandable catheter and related methods of manufacture and use

ABSTRACT

A medical device may include an expandable energy delivery array reciprocally movable between a first configuration and a second configuration. The expandable energy delivery array may include a first assembly having a first proximal end piece, a first distal end piece, and one or more first energy transfer elements extending between the first proximal and first distal end pieces, and a second assembly having a second proximal end piece, a second distal end piece, and one or more second energy transfer elements extending between the second proximal and second distal end pieces. The second proximal end piece may be proximal to the first proximal end piece and the second distal end piece may be distal to the first distal end piece.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/864,292, filed Aug. 9, 2013, the disclosure of which is incorporatedherein by reference in its entirety.

FIELD

Examples of the present disclosure relate generally to medical devices,and methods for manufacturing and using these medical devices. Inparticular, examples of the present disclosure relate to catheters andmethods for manufacturing and using catheters for applying energy totissue (e.g., airway passageways in a lung) in a minimally invasiveprocedure.

BACKGROUND OF THE INVENTION

Chronic obstructive pulmonary disease (COPD) includes conditions suchas, e.g., chronic bronchitis and emphysema. COPD currently affects over15 million people in the United States alone and is currently the thirdleading cause of death in the country. The primary cause of COPD is theinhalation of cigarette smoke, responsible for over 90% of COPD cases.The economic and social burden of the disease is substantial and isincreasing.

Chronic bronchitis is characterized by chronic cough with sputumproduction. Due to airway inflammation, mucus hypersecretion, airwayhyper-responsiveness, and eventual fibrosis of the airway walls,significant airflow and gas exchange limitations result.

Emphysema is characterized by the destruction or damage of the lungparenchyma. This destruction of the lung parenchyma leads to a loss ofelastic recoil and tethering which maintains airway patency. Becausebronchioles are not supported by cartilage like the larger airways, theyhave little intrinsic support and therefore are susceptible to collapsewhen destruction of tethering occurs, particularly during exhalation.

Acute exacerbations of COPD (AECOPD) often require emergency care andinpatient hospital care. An AECOPD is defined by a sudden worsening ofsymptoms (e.g., increase in or onset of cough, wheeze, and sputumchanges) that typically last for several days, but can persist forweeks. An AECOPD is typically triggered by a bacterial infection, viralinfection, or pollutants, which manifest quickly into airwayinflammation, mucus hypersecretion, and bronchoconstriction, causingsignificant airway restriction.

Despite relatively efficacious drugs (e.g., long-acting muscarinicantagonists, long-acting beta agonists, corticosteroids, andantibiotics) that treat COPD symptoms, a particular segment of patientsknown as “frequent exacerbators” often visit the emergency room andhospital with exacerbations. These patients also have a more rapiddecline in lung function, poorer quality of life, and a greatermortality risk.

Reversible obstructive pulmonary disease includes asthma and reversibleaspects of COPD. Asthma is a disease in which bronchoconstriction,excessive mucus production, and inflammation and swelling of airwaysoccur, causing widespread but variable airflow obstruction therebymaking it difficult for the asthma sufferer to breathe. Asthma isfurther characterized by acute episodes of airway narrowing viacontraction of hyper-responsive airway smooth muscle.

The reversible aspects of COPD include excessive mucus production andpartial airway occlusion, airway narrowing secondary to smooth musclecontraction, and bronchial wall edema and inflation of the airways.Usually, there is a general increase in bulk (hypertrophy) of the largebronchi and chronic inflammatory changes in the small airways. Excessiveamounts of mucus are found in the airways, and semisolid plugs of mucusmay occlude some small bronchi. Also, the small airways are narrowed andshow inflammatory changes.

In asthma, chronic inflammatory processes in the airway play a centralrole in increasing the resistance to airflow within the lungs. Manycells and cellular elements are involved in the inflammatory processincluding, but not limited to, mast cells, eosinophils, T lymphocytes,neutrophils, epithelial cells, and even airway smooth muscle itself. Thereactions of these cells result in an associated increase in sensitivityand hyperresponsiveness of the airway smooth muscle cells lining theairways to particular stimuli.

The chronic nature of asthma can also lead to remodeling of the airwaywall (e.g., structural changes such as airway wall thickening or chronicedema) that can further affect the function of the airway wall andinfluence airway hyper-responsiveness. Epithelial denudation exposes theunderlying tissue to substances that would not normally otherwisecontact the underlying tissue, further reinforcing the cycle of cellulardamage and inflammatory response.

In susceptible individuals, asthma symptoms include recurrent episodesof shortness of breath (dyspnea), wheezing, chest tightness, and cough.Currently, asthma is managed by a combination of stimulus avoidance andpharmacology.

Bronchiectasis is a condition where lung airways become enlarged,flabby, and/or scarred. In the injured areas, mucus often builds up,causing obstruction and/or infections. A cycle of repeated infectionsmay continue to damage the airways and cause greater mucus build-up.Bronchiectasis can lead to health problems such as respiratory failure,atelectasis, and heart failure.

Strategies for managing COPD and other conditions of the lung includesmoking cessation, vaccination, rehabilitation, and drug treatments(e.g., inhalers or oral medication). Drug treatments of COPD conditions,such as, e.g., mucus production, inflammation, and bronchoconstrictionoften suffer from poor patient compliance. That is, certain patients maynot accurately administer prescribed doses, reducing the efficacy oftreatment. For drug treatments utilizing inhalation, there is also anaccompanying drug loss due to upper airway entrapment, which may lead toan over-prescription of active drugs. Also, inhalation treatments can beineffective at treating smaller airways of the lung (e.g., airways thatare smaller than 2 mm). For drug treatments utilizing oraladministration, there is an accompanying systemic loss which also leadsto an over-prescription of active drugs. The over-prescription of drugsmay result in suboptimal treatment and/or a build-up of toxins withinthe lungs and/or other organ systems. In other situations, drugs may notbe deposited evenly to areas of the lungs because of particle sizeand/or blockage of airways preventing the drugs from reaching distalregions of the lungs (e.g., a heterogeneous delivery of drugs).Blockages may be caused by mucus and narrowing of the airway due toinflammation and remodelling.

The use of radiofrequency (RF) energy in medical applications is rapidlyincreasing. RF energy can be used to treat a variety of conditionsaffecting numerous body systems, such as, e.g., the respiratory system,the circulatory system, the digestive system, the immune system, themuscular system, among others. Various non-drug energy deliveryprocedures for, among other things, treatment of COPD, such as, e.g.,severe persistent asthma, for which inhaled corticosteroids andlong-acting beta-agonists are an insufficient treatment. In order toapply the energy delivery procedures, a catheter may be positioned todeliver thermal energy to a body lumen, such as a lung airway wall, forreducing excessive airway smooth muscle (ASM), and clear the air pathwaywithin the trachea or lungs of a patient. The catheter may include anelectrode array at a distal portion, which may be manually expanded toposition the electrode array in communication with the airway wall. Theelectrode array may be coupled to one or more thermocouple wires fordetermining temperature of the electrode array to control the thermalenergy delivered to the airway wall.

Conventionally, the electrode array can include elongated electrodes,which are welded together and coupled to hypotubes at their distal andproximal ends. Since the electrode array and the hypotubes areconductive to each other, welding of the electrode array only allows formonopolar design of delivering electrical energy to the electrode array.Moreover, in conventional arrangements, less space is available for thethermocouple wire to extend proximally through a proximal hypotubeattached to the electrode array due to welding of the electrode array.

Therefore, there exists a need for an improved catheter design thatpermits different configurations (including, e.g., monopolar or bipolarconfigurations) for the delivery of electrical energy to body lumens,and increases effective space available for, among other things,thermocouple wire attachment. The improved catheter designs would alsoreduce the number of steps needed to assemble and/or manufacture theelectrode array by, e.g., eliminating the need for welding togethermultiple electrodes of the electrode array. In other examples, thereexists a need for other improvements. For example, certain electrodearrays, e.g., monopolar electrode arrays, may create uneven heatingdistribution, and may concentrate heating in the regions surrounding theelectrodes to undesirable levels.

SUMMARY OF THE INVENTION

In one example, a medical device may include an expandable electrodeassembly reciprocally movable between a first configuration and a secondconfiguration. The expandable electrode assembly may include a firstplurality of longitudinally extending legs formed in a first partiallytubular member, a second plurality of longitudinally extending legsformed in a second partially tubular member, a first end piece formed byfirst ends of the first and second partially tubular members, and asecond end piece formed by second ends of the first and second partiallytubular members, wherein a portion of the second partially tubularmember is configured to be received in a portion of the first partiallytubular member.

Various examples of the medical device may include one or more of thefollowing features: legs of first partially tubular membercircumferentially alternate with legs of the second partially tubularmember; the first ends of the first and second partially tubular membersare substantially C-shaped or other shapes that are capable of beingcoupled, and the first end piece is formed by inserting the first end ofthe second partially tubular member into a volume partially defined bythe first end of the first partially tubular member; when a portion ofthe second partially tubular member is received in a portion of thefirst partially tubular member, the first and second plurality oflongitudinally extending legs define an expandable electrode array, suchas a basket; the second end piece further includes an offset thatextends longitudinally beyond the first end piece; an activation elementdisposed through first and second end pieces, the activation elementconfigured to move the plurality of legs radially outward from the firstconfiguration to the second configuration, and reciprocally back to thefirst configuration or the legs can have a shape memory effect thatrestores the legs to the first configuration; the activation element iselectrically conductive and configured to deliver electrical energy toat least one of the first and second plurality of longitudinallyextending legs; each of the first and second plurality of longitudinallyextending legs includes: a first insulated section; a second insulatedsection, and an exposed electrically conductive section between thefirst and second insulated sections; the first and second end pieces areinsulated; the second end of the second partially tubular memberincludes a circumferentially extending gap between first and secondC-shaped portions, at least one of the second plurality oflongitudinally extending legs extends from the first C-shaped portion,and at least one of the second plurality of longitudinally extendinglegs extends from the second C-shaped portion; the first end of thefirst partially tubular member includes a circumferentially extendinggap between first and second C-shaped portions; at least one of thefirst plurality of longitudinally extending legs extends from the firstC-shaped portion of the first partially tubular member, and at least oneof the first plurality of longitudinally extending legs extends from thesecond C-shaped portion of the first partially tubular member; the firstend piece further includes a first longitudinally extending gap disposedbetween circumferential ends of the first end piece, and the second endpiece further includes a second longitudinally extending gap disposedbetween circumferential ends of the second end piece; a tube disposedaround at least one leg of the first or second plurality of legs; athird longitudinally extending gap disposed in either first or secondend of the first partially tubular member, the tube extending throughthe third longitudinally extending gap when the basket is in an expandedconfiguration; an endcap disposed through the first or secondlongitudinally extending gap, the endcap configured to prevent rotationof the first partially tubular member relative to the second partiallytubular member.

In another example, a medical device may include a first partiallytubular member having a first end, a second end, a first plurality oflegs extending between the first and second ends of the first partiallytubular member. The medical device may include a second partiallytubular member including a first end, a second end, and a secondplurality of legs extending between the first and second ends of thesecond partially tubular member, wherein the first ends of the first andsecond partially tubular members are coupled together, the second endsof the first and second partially tubular members are coupled together,and the first and second plurality of legs are disposed about alongitudinal axis of the medical device.

Various examples of the medical device may include one or more of thefollowing features: legs of first partially tubular membercircumferentially alternate with legs of the second partially tubularmember; and the first and second ends of the first and second partiallytubular members are C-shaped.

In another example, a method of delivering energy to a body lumen usinga medical device may include inserting the medical device into the bodylumen. The medical device may include a basket reciprocally movablebetween a collapsed configuration and an expanded configuration. Thebasket may include a first plurality of longitudinally extending legsformed in a first partially tubular member, a second plurality oflongitudinally extending legs formed in a second partially tubularmember, a first end piece formed by first ends of the first and secondpartially tubular members, and a second end piece formed by second endsof the first and second partially tubular members. The method may alsoinclude delivering electrical energy to the body lumen via at least oneof the first or second plurality of legs.

In a further example, the legs of first partially tubular membercircumferentially may alternate with legs of the second partiallytubular member.

In yet another aspect, the present disclosure may be directed to amedical device. The medical device may include an expandable energydelivery array reciprocally movable between a first configuration and asecond configuration. The expandable energy delivery array may include afirst assembly having a first proximal end piece, a first distal endpiece, and one or more first energy transfer elements extending betweenthe first proximal and first distal end pieces, and a second assemblyhaving a second proximal end piece, a second distal end piece, and oneor more second energy transfer elements extending between the secondproximal and second distal end pieces. The second proximal end piece maybe proximal to the first proximal end piece, and the second distal endpiece may be distal to the first distal end piece.

Various examples of the present disclosure may include one or more ofthe following features: wherein the first and second assemblies may beelectrically insulated from one another; wherein the first and secondproximal end pieces may be separated by an insulating element; whereinthe first and second proximal end pieces may be longitudinally separatedby the insulating element; wherein the first and second distal endpieces may be longitudinally separated by an insulating element; whereinthe first and second energy transfer elements may radially alternatewith one another relative to a longitudinal axis of the medical device;wherein the second energy transfer elements may extend through a notchdisposed in an outer radial surface of the second distal end piece;wherein the first energy transfer elements may be disposed further froma longitudinal axis of the energy delivery array than the second energytransfer elements; wherein the second assembly may be configured todeliver energy through a body tissue to the first assembly; furtherincluding an activation element that may extend from a proximal end ofthe medical device through the first and second assemblies, theactivation element being coupled to the second distal end piece; whereinlongitudinal movement of the activation element may be configured toreciprocally move the energy delivery array between the first and secondconfigurations, wherein the first configuration is a collapsedconfiguration and the second configuration may be a radially expandedconfiguration; wherein the activation element may be configured todeliver RF energy to the second assembly; wherein each of the first andsecond transfer elements may include an active region defined atproximal and distal portions by insulating regions, wherein the activeregion may be configured to deliver RF energy to body tissues when incontact with the body tissues, and the insulating regions are notconfigured to deliver RF energy to body tissues at any time; wherein theactive region of at least one first or second energy transfer elementmay include at least one temperature sensing element configured to sensea temperature of the active region or of body tissue; wherein the energydelivery array may be configured to deliver energy to body tissues in abipolar configuration.

In yet another aspect the present disclosure may be directed to amedical device. The medical device may be an expandable energy deliveryarray reciprocally movable between a first configuration and a secondconfiguration. The expandable energy delivery array may include one ormore first energy transfer elements, and one or more second energytransfer elements. The one or more first energy transfer elements mayalternate with the one or more second energy transfer elements radiallyabout a longitudinal axis of the energy delivery array, and the one ormore first energy transfer elements may be spaced further from thelongitudinal axis of the energy delivery array than the one or moresecond energy transfer elements.

Various aspects of the present disclosure may also include the followingfeature: an activation element that may extend from a proximal endtowards a distal end of the medical device, the activation elementconfigured to deliver energy to the one or more second energy transferelements.

In yet another aspect, the present disclosure may be directed to amethod of delivering energy to a body. The method may include insertingan energy delivery array having one or more first energy transferelements and one or more second energy transfer elements into a lumen ofthe body. The one or more first energy transfer elements may be disposedfurther from a longitudinal axis of the energy delivery array than theone or more second energy transfer elements. The method may also includeradially expanding the one or more first and second transfer elements tocontact tissues defining the lumen, and delivering energy from the oneor more second energy transfer elements, through the tissues, to the oneor more first energy transfer elements.

Various aspects of the present disclosure may include one or more of thefollowing features: radially expanding the one or more first and secondtransfer elements by longitudinally moving an activation elementextending through a space defined by the first and second energytransfer elements; and delivering energy to the one or more secondenergy transfer elements via the activation element.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary examples of the presentdisclosure and together with the description, serve to explainprinciples of the disclosure.

FIG. 1 is a perspective view of a distal electrode array of an exemplarycatheter in a collapsed configuration, according to an example of thepresent disclosure.

FIGS. 2A-2H illustrate exploded, partially exploded, and assembled viewsof an exemplary electrode array.

FIGS. 3A-3E depict alternative configurations of an exemplary electrodearray.

FIGS. 4A-4B depicts an exemplary cap for use with the exemplaryelectrode arrays disclosed herein.

FIG. 5 is a perspective view of the distal electrode array of FIG. 1 inan expanded configuration.

FIGS. 6A-6D illustrate exploded, partially exploded, and assembled viewsof another exemplary electrode array.

FIG. 7 is a perspective view of an energy delivery array in a collapsedconfiguration, according to another example of the present disclosure.

FIGS. 8-11 illustrate partially assembled views of an energy deliveryarray, such as the energy delivery array of FIG. 7.

DESCRIPTION OF THE EXAMPLES

Reference will now be made in detail to exemplary examples of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.The term “distal” may refer to the end farthest away from a user whenintroducing a device into a patient. By contrast, the term “proximal”may refer to the end closest to the user when placing the device intothe patient.

Examples of the present disclosure relate to medical devices used forapplying energy to tissue during minimally invasive procedures. Forexample, examples of a disclosed catheter and method of use arecontemplated. In some examples, an expandable catheter, e.g., aradiofrequency (RF) catheter, including elongated electrodes (configuredin an expandable electrode array) may be advanced into tissue of apatient's body. The catheter may be bipolar or monopolar, and may beconfigured to expand within a body lumen to deliver electrical energy toelongated electrodes located at a distal portion of the catheter. Thecatheters may be constructed without welding the electrodes together. Inparticular, the catheter can be used in a procedure, such as, e.g., anenergy delivery procedure, where energy may be transferred to targettissue (e.g., lung tissue) by the RF catheter electrode. Energy deliveryprocedures may use the catheter to deliver thermal energy to an airwaywall in a controlled manner to eliminate or otherwise reduce excessiveASM. To apply an energy during an energy delivery procedure, thecatheter may be positioned at a desired location within the airway. Anelectrode cage or array may be disposed at a distal portion of thecatheter, and may be selectively expanded to contact the airway wall.The RF electrodes may be expanded manually by squeezing a handle (oractuating another suitable actuator) of the catheter by applying anappropriate expansion force.

Initially, those of ordinary skill in the art will understand that anyof the examples disclosed herein may include one or more of the featuresdiscussed in connection with another of the other examples disclosedherein.

FIG. 1 is a perspective view of a distal portion of an exemplarycatheter 100 having an electrode array or cage 102 in a collapsedconfiguration. Catheter 100 may be configured to be introduced into apatient's body through an incision or a suitable natural opening, suchas e.g., the mouth or nose. In one exemplary example, catheter 100 maybe configured to be advanced to a desired location within a patient'sbody via a suitable introduction sheath (not shown), such as, e.g., anendoscope, bronchoscope, or other type of scope. The proximal end of thecatheter may be connected to a hub assembly, a handle (not shown), oranother suitable actuator for operating cage 102. More particularly, thehandle or actuator may be configured to transition cage 102 between afirst collapsed configuration (e.g., as shown in FIG. 1) and a secondexpanded configuration (e.g., as shown in FIG. 5). The handle may beergonomically designed and may include a variety of components such as,e.g., steering controls and a pull wire for selectively positioning adistal portion of catheter 100. Further, the handle may include one ormore ports in communication with one or more working channels of theintroduction sheath for inserting other medical device(s).

The distal portion of catheter 100 may be used to ablate or otherwisedeliver energy to tissue inside the body of a patient for treatment. Asshown in FIG. 1, the distal portion of catheter 100 may includeelectrode cage 102, an activation element 104 (such as, e.g., a pullwire), expansion supporters 106 and 107, and a hypotube or cap 108.Electrode cage 102 may be formed from two separate electrode tubesoperably received into one another, as discussed below in greaterdetail. The electrode tubes may include one or more electrode ribbons 10and 11, each of which may be separated from one another by alongitudinal gap 18, and may be configured into monopolar or bipolarconfigurations for delivering energy tissue. as described below. Thedistal and proximal ends of the electrode tubes may have an opening forallowing activation element 104 to extend distally from the proximalportion of catheter 100 through electrode cage 102. Unlike conventionalelectrode cages or electrode arrays, electrode cage 102 may beconstructed without welding electrodes 10, 11 together on catheter 100,and may be operated in a bipolar configuration by isolating positiveelectrodes from negative electrodes.

A length of activation element 104 extending through electrode cage 102may also extend through expansion supporters 106, 107. Expansionsupporters 106, 107, the longitudinal gaps between the electrodes 10,11, and a hypotube 108 may facilitate buckling of electrodes 10, 11. Thebuckling of electrodes 10, 11 may allow electrode cage 102 toreciprocally move between the collapsed configuration and an expandedconfiguration, in which each electrode of the electrode cage bowsradially outward. In some examples, electrodes 10, 11 may include ashape memory material that restores electrodes 10, 11 to the collapsedor expanded configuration. Hypotube or cap 108 may be located at adistal end of the electrode cage 102 to support and provide resilienceto electrode cage 102.

FIGS. 2A-2H, 3A-3E, and 4A-4B illustrate various views of the componentsand assemblies that make up electrode cage 102 depicted in FIG. 1. Thesubsequent disclosure describes an exemplary example of formingelectrode cage 102 from electrode panels 202 and 203, (referring toFIGS. 2A-2H). Electrode cage 102 may include a channel 302 (referring toFIGS. 3A-3C) for a thermocouple (TC) element 304 (e.g., wire), and ashrink tube 306 (referring to FIGS. 3D-3E) configured to provide strainrelief to electrode cage 102. Electrode panels 202, 203 can be coupledto an end cap 402 (FIG. 4A), activation element 104 (FIG. 4B), expansionsupporters 106, 107 and hypotube 108 (FIG. 5) to manufacture the distalportion of catheter 100.

In one example, each of electrode panels 202, 203 (referring to FIG. 2A)may be formed from a single sheet of any biocompatible material that isboth flexible and electrically conductive in nature. The sheet may berectangular or may be another suitable shape. The biocompatible materialmay include, but is not limited to, stainless steel, nitinol, otherknown electrically conductive surgical/medical materials, and anycombinations thereof. During manufacture, electrode panel 202 may beformed from a sheet having a distal portion 22 and a proximal portion 24that can be machined or etched to achieve a variable thicknesscross-section. Similarly, electrode panel 203 may be for formed from asheet having a distal portion 23 and a proximal portion 25. The distalportions 22, 23 and proximal portions 23, 25 of the various sheets maybe also machined such that they are wider relative to a remainder of thesheet(s).

Longitudinal sections may be removed from between distal portion 22 andproximal portion 24 of electrode panel 202 to form electrodes 10 and 11separated by a longitudinal gap 18. Similarly, the electrode panel 203may have electrode ribbons 12 and 13 separated by a longitudinal gap 20.Although each of the electrode panels 202, 203 have been shown to havetwo electrodes, a greater or lesser number of electrodes may be utilizedin alternative examples. The removal of the longitudinal sections maycause the transverse lengths of distal portion 22 and proximal portion24 of electrode panel 202 to become relatively longer than the combinedwidth of electrodes 10, 11 and longitudinal gap 18. Similarly, theremoval of the longitudinal sections may cause the transverse lengths ofdistal portion 23 and proximal portion 25 of electrode panel 203 tobecome relatively longer than the combined width of electrodes 12, 13and longitudinal gap 20, The electrodes 10, 11, 12, and 13 may belongitudinally extending legs having substantially the same or avariable cross-section, each of which may be less than the width ofinclusive longitudinal gaps 18, 20. As shown, electrodes 12, 13 may havea thicker cross-section at an interior portion (e.g., at a middle orcentral portion) for providing additional strength to electrodes 12, 13and space for creating a channel. The sheets utilized to form electrodepanels 202, 203 may have relatively different widths so that theelectrode panels 202, 203 have different diameters when rolled.

Subsequently, electrode panels 202, 203 may be rolled to form apartially tubular member (FIG. 2B) such that each of electrode panels202, 203 has a radial profile. When rolled, electrode panels 202, 203may form electrode tubes 204, 205 respectively. The radial profile maycreate a C-shaped cam surface at the longitudinal ends of the electrodetubes 204, 205, allowing electrode tube 204 to surround and mate withelectrode tube 205, forming electrode cage 102. For instance, radiallydistal portion 22 and proximal portion 24 of the electrode tube 204 mayoperably receive the respective radially distal and proximal portions23, 25 of electrode tube 205 using any suitable mechanism (FIG. 2C),such as, e.g., welding, coaxial sliding, friction fitting, screwfitting, and gluing, among others. Unlike in conventional catheters,where formation of an electrode cage or array may be achieved by weldingthe electrodes as a bundle, electrode tubes 204, 205 may be insteadreceived into one another (e.g., one may be inserted into a volumepartially defined by the other). Consistent with this, electrode cage102 may have a C-shaped opening at its distal and proximal portions. Theouter diameter and inner diameter of electrode tubes 204, 205 maydetermine the effective force responsible for interlocking electrodetubes 204, 205 to form electrode cage 102. Such interlocking of theelectrode tubes 204, 205 may allow for expansion of electrode cage 102about the distal portions 22, 23 and the proximal portions 24, 25 ofelectrode tubes 204, 205. Additionally, the interlocking of the C-shapedradial ends may prevent rotation of the electrodes 10, 11, 12, and 13relative to each other. Electrode tubes 204, 205 may be retainedrelative to one another via an interference or friction fit.

Further, the angular position of the electrodes 10, 11, 12, and 13 inelectrode tubes 204, 205 can be controlled by the orientation oflongitudinal gaps 18, 20 between them. That is, electrode tubes 204, 205may be rotated relative to one another (as shown in FIGS. 2D and 2E) to,e.g., control the spacing between electrodes 10, 11, 12, and 13.Coplanarity of the distal and proximal edges of electrode tubes 204, 205may be maintained to properly align the electrodes. Moreover,longitudinal gaps 18, 20 may allow for compression and/or buckling ofelectrode cage 102 during operation.

In electrode cage 102, inner electrode tube 205 may be detachablyconnected or permanently coupled to outer electrode tube 204 with eithereven spacing (FIG. 2D) or uneven spacing (FIG. 2E) between electrodes10, 11, 12, and 13. Electrodes 10, 11, 12, and 13 may be spaced evenlyalong the circumference of electrode cage 102 to account for thediametric difference(s) of inner electrode tube 205 with respect toouter electrode tube 204. The circumference of the electrode cage 102 atits longitudinal ends may account for uneven spacing between theelectrodes 10, 11, 12, and or 13.

Electrode cage 102 may be monopolar or bipolar based on insulationarrangements between electrodes 202, 203. If electrodes 10, 11, 12, and13 are not insulated from each other at one or both of distal portions22, 23 and proximal portions 24, 25, electrode cage 102 may operate inmonopolar fashion (FIG. 2F). If electrodes 10, 11, 12, and 13 areinsulated from each other at distal portions 22, 23 and proximalportions 24, 25, electrode cage 102 may operate in a bipolar fashion(FIG. 2G). Moreover, as shown in FIGS. 2F and 2G, portions P ofelectrodes 11 (represented by a cross-hatch) may be insulated to createa focused region at an interior portion of electrodes 10, 11 fordelivery of electrical energy. Similarly, portions of electrodes 12, 13may be insulated to create a focused region for delivery of electricalenergy. In order to achieve the above-described insulationcharacteristic, electrode tubes 204, 205 may be coated with any suitableinsulative material, for example, a hydrophilic layer of polymers knownin the art at contact regions disposed at distal portions 22, 23 andproximal portions 24, 25. Other suitable insulative coatings may includeceramic, silicone, glass, and any other non-conductive, biocompatiblematerial The coating may occur prior to the assembly of electrode tubes204, 205. The coating of electrode tubes 204, 205 may promote thelocalization of radiofrequency (RF) electrical energy at interiorportions of electrode tubes 204, 205. The insulative material may beapplied by a variety of coating process including vapor deposition,dipping, spraying, or other processes that are conducive for small partsand thin films. The insulations described above may also serve toelectrically separate electrodes 10-13 so that cage 102 may operate in abipolar configuration.

An offset X may be disposed between electrode tubes 204, 205 (FIG. 2H),and may be allotted at distal end 26 of electrode cage 102 to aid in theassembly of electrode cage 102. For example, offset X may allow innerelectrode tube 205 to be compressed independently from outer electrodetube 204. Further, electrical energy may be supplied to inner electrodetube 205 by activation element 104 if, for example, in the bipolarconfiguration, distalmost surfaces 28, 30 (referring to FIG. 2H) ofouter and inner electrode tubes 204, 205 respectively are exposed tocontact a portion of activation element 104 that is conductingelectrical energy. In a bipolar configuration, e.g., distalmost surface28 may be insulated from distalmost surface 30, which may be in contactwith activation element 104 and receiving electrical energy therefrom.

Referring to FIG. 3A, proximal and/or distal ends of electrode tubes204, 205 may be generally C-shaped. However, those of ordinary skillwill recognize that the proximal and/or distal ends of tubes 204, 205may include any suitable configuration. When electrode tubes 204, 205are interlocked, they may define a longitudinally extending gap 302. Theproximal and/or distal ends of electrode tubes 204, 205 may partiallydefine an incomplete annular channel 303 due to the presence of gap 302.In one example, gap 302 may be formed in an external portion ofelectrode tubes 204, 205, and be configured provide access to channel303 for, e.g., thermocouple (TC) element(s) (e.g., wires) 304 thatextend from a proximal portion of catheter 100. TC element(s) 304 may beconfigured to determine a temperature of electrodes 10, 11, 12, and 13(or surrounding tissue which the electrodes may contact) duringoperation. In another example, elements (e.g., wires) for supplyingelectrical energy to electrodes 10, 11, 12, and 13 may be routed throughchannel 303 via gap 302 from the proximal portion of catheter 100. Asshown in FIG. 3A, electrode cage 102 may expand about its radial ends,and thus access to electrodes 10, 11, 12, and 13 through electrode cage102 for soldering or welding of TC element 304 may be relatively easycompared to other configurations. The TC element 304 may followinsulation coating on electrodes 10, 11, 12, and 13, and may be disposedon electrodes 10, 11, 12, and 13 prior to the assembly of electrodetubes 204, 205. Further, TC elements 304 may be secured within channel303 through an additional compression applied on respective electrodetubes 204, 205, or by positioning TC element(s) 304 into channel 303 andsubsequently attaching TC element(s) 304 to an interior surface ofchannel 303 by bonding, welding, or soldering, or by another suitablesecuring mechanism.

Referring to FIG. 3E, the C-shaped ends of electrode tubes 204, 205 mayfurther define a longitudinally extending gap 305 to accommodate ashrink tube 306. Gap 305 may be substantially parallel to gap 302, andmay be transposed about a circumference of the C-shaped ends ofelectrode tubes 204, 205 with respect to gap 302. Shrink tube 306 may beconfigured to provide strain relief for the electrode-attached elementssuch as TC element 304 and electrodes 10, 11, 12, and 13. In one example(referring to FIG. 3B-3E), gap 305 may receive TC element 304 and shrinktube 306. In an alternative example (referring to FIGS. 3B-3E),electrode tubes 204, 205 may be oriented in electrode cage 102 to createa single channel 302 at one end of electrode cage 102 for receiving TCelement 304 and shrink tube 306. Channel 302 may decouple one end of theelectrode, for example, the electrode 10, from a remainder of electrodetube 204. The C-shaped ends of electrode tubes 204, 205 may define acircumferentially extending gap 310 that decouples electrodes 11 and 12at one end (e.g., the proximal or distal end) of electrode tubes 204,205. In another example (referring to FIG. 3C), a channel 311 may becreated between electrode 10 and shrink tube 306 disposed over a thickercross-section of electrode 10. In this example, channel 311 may receiveTC element 304 along a thicker cross-section of electrode 10 and aC-shaped proximal or distal end of electrode cage 102. Shrink tube 306may be slid through channel 311 as well as over TC element 304(referring to FIG. 3D). Shrink tube 306 may be subsequently heated topermanently affix shrink tube 306 over TC element 304 to provide strainrelief. Channel 311 may provide additional stiffness to the electrodes,and may produce improved tissue airway contact when electrode cage 102is expanded. Referring to FIG. 3E, the outer electrode tube 204 may fixchannel 302 adjacent to the distal end of electrode cage 102. However,channel 302, which may be disposed in the outermost electrode electrodes10, 11 at the proximal end of electrode cage 102, may be gripped byshrink tube 306.

Further, once electrode tubes 204, 205 are interlocked to form electrodecage 102, an end cap 402 (referring to FIG. 4A) may be inserted into thedistal end of electrode cage 102 to maintain the inner diameter andorientation of electrode cage 102. In some examples, cap 402 may urgeinner electrode tube 204 radially outward and against outer electrodetube 205, thereby creating a friction fit therebetween. A coaxial hole408 disposed in end cap 402 may be created to allow activation element104 to distally pass through it. End cap 402 may also include a rib 404to engage with channel 302 created by electrode tubes 204, 205 at theC-shaped distal end of electrode cage 102. Rib 404 in end cap 402 maymaintain orientation of electrode tubes 204, 205 with respect to oneanother. Rib 404 may also urge opposing ends of inner electrode tube 204away from one another, thereby enlarging a diameter of inner electrodetube 204 and consequently urging it against outer electrode tube 205.End cap 402 may be modified or configured to include insulation and toaccommodate the offset X (see FIG. 2H) between electrode tubes 204, 205.In a bipolar configuration having C-shaped contact regions of theelectrodes 10, 11, 12, and 13 insulated from each other at the distalend of electrode cage 102, modified end cap 402 may be configured toconduct electrical energy from activation element 104 to only one of theelectrode tubes, for example, the electrode tube 205. Thus, in someexamples, modified end cap 402 may be placed in communication withconducting distal ends of the C-shaped contact regions of anycombination of electrodes 10, 11, 12, and 13.

Referring to FIG. 4B, activation element 104 may extend distally fromwithin electrode cage 102 through channel 302 in at least one example. Adistal end of activation element 104 can include a stopper 406 thatdistally engages and passes through coaxial hole 408 in end cap 402.Stopper 406 may include a diameter that is larger than a remainder ofactivation element 104. End cap 402 may be inserted in communicationwith the distal end of electrode cage 102. Stopper 406 may help providestability, grip and assist in reciprocal movement of electrode cage 102from a collapsed configuration to an expanded configuration duringoperation.

FIG. 5 illustrates electrode cage 102 in the expanded configuration.Configurations of electrode cage 102 based on orientation of electrodetubes 204, 205 and spacing between electrodes 10, 11, 12, and 13 andactivation element 104 may be provided with expansion supporter(s) 106,107 to assist in an electrode buckling direction and to preventelectrode inversion. Expansion supporters 106, 107 may also function asalignment components to maintain spacing between electrodes 10, 11, 12,and 13 when they are in the expanded configuration. Each of expansionsupporters 106, 107 may include a longitudinal lumen disposed thereinfor receiving a portion of activation element 104.

A system may include a controller (not shown) and a standard flexiblebronchoscope including catheter 100. The controller may be configured todeliver RF electrical energy to electrodes 10, 11, 12, and 13 at thedistal portion of catheter 100. During operation, catheter 100 may be,while in collapsed configuration, distally advanced into a body lumen,such as, e.g., a bronchial tree or airway of lungs through a naturalopening of the body, such as, e.g., the nose or mouth. The bronchoscopemay be then navigated to a target treatment site, for example, the mostdistal airway in a targeted bronchial lobe. Once a distal end portion ofcatheter 100 is positioned at the target treatment site, electrode cage102 may be expanded to make electrodes 10, 11, 12, and 13 contact aninner wall of the airway. Expansion of electrodes 10-13 may be limitedwhen contact is made with the inner airway wall. Subsequently, thecontroller, which may be connected to a hub assembly of catheter 100 atthe proximal end, may be activated to deliver electrical energy viaactivation element 104 and electrodes 10, 11, 12, and 13 to thetreatment site. The electrical energy may be delivered in monopolar orbipolar fashion by electrodes 10, 11, 12, and 13 to deliver energy(e.g., RF, ultrasonic, or thermal energy) to tissue, such as, e.g., lungtissue. Each of such activation of electrodes 10, 11, 12, and 13 may becontrolled to deliver RF electrical energy at a certain power,temperature and/or period of time, in order to affect a certaintreatment protocol, e.g., 10 seconds intervals, at a temperature ofabout 65 degrees Celsius, and up to about 15 Watts of power, in the caseof a monopolar application. It should be noted that the activationperiod may be increased or decreased, if desired. However, the bipolaractivation of electrodes 10, 11, 12, and 13 may reduce this activationperiod relative to the monopolar activation period. The deliveredelectrical energy may be controlled to create a precise delivery ofthermal energy to the airway wall, e.g., to eliminate or otherwisereduce excessive ASM, and decrease the ability of the airways toconstrict, thereby reducing the severity of COPD or other bronchialconditions. In some examples, this may reduce the frequency of asthmaattacks. When the lung tissue or ASM is sufficiently reduced, ortreatment is otherwise completed, e.g., the controller may bedeactivated and activation element 104 may be relaxed to release thebuckling of electrodes 10, 11, 12, and 13 to return electrode cage 102to the collapsed configuration, so that catheter 100 may be removed fromwithin the patient.

This energy delivery procedure may be minimally invasive and may beperformed in one or more outpatient procedure visits, each treating adifferent area of the lungs and scheduled approximately one or more(e.g., three) weeks apart.

Although the examples described above are disclosed in the context ofuse with a bronchoscope, those skilled in the art will understand thatthe principles disclosed above can be applied to other types of devicesand can be implemented in different ways without departing from thescope of the invention as defined by the claims. In particular,constructional details, including manufacturing techniques andmaterials, are well within the understanding of those of ordinary skillin the art and have not been disclosed in detail herein. These and othermodifications and variations are well within the scope of the presentdisclosure and can be envisioned and implemented by those of ordinaryskill in the art.

With reference now to FIGS. 6A-6D, there is depicted another distalenergy delivery assembly 700, in accordance with a further example ofthe present disclosure. Energy delivery assembly 700 may include one ormore features of the aforementioned examples discussed herein,including, for example, electrode cage 102.

Energy delivery assembly 700 may include a plurality of electrode tubes702, 704. Like electrode tubes 204, 205, electrode tubes 702, 704 may befabricated from rolling flattened electrode panels (not shown).Electrode tube 704 may be substantially similar to one or both ofelectrode tubes 204, 205. For example, electrode tube 704 may include aplurality of electrodes 722, 724 separated by a longitudinal gaptherebetween. Although only two electrodes 722, 724 are shown, a greateror lesser number of electrodes 722, 724 may be provided as desired.Electrodes 722, 724 may be coupled together by proximal and distalportions 730, 732, as described above in connection with theaforementioned examples. As a result of rolling, each of proximal anddistal portion 730, 732 may include a C-shaped or substantiallycylindrical configuration. Proximal and distal portions 730, 732 mayeach define a through passageway therein. One or both of electrodes 722,724 may include insulation 726 (e.g., a suitable insulative covering)disposed on a portion of electrodes 722, 724. For example, as shown inFIG. 6A, electrodes 722, 724 may include insulation 726 disposed on aproximal portion, including proximal portion 730 of electrode tube 704.Similarly, electrodes 722, 724 may include insulation 728 disposed on adistal portion, including distal portion 732 of electrode tube 704. Asdiscussed above, in some examples, proximal and distal portions 730, 732may not include insulation. Electrodes 722, 724 may include an activeregion that does not include any insulation and disposed betweeninsulations 726, 728. The active region may be configured to contact anddeliver energy to target tissue.

Electrode tube 702 may also include two electrodes 706, 708 separated bya longitudinal gap. However, any suitable number of electrodes may beprovided. Electrodes 706, 708 may be substantially similar to electrodes722, 724. For example, electrodes 706, 708 may be coupled to one anothervia a proximal portion 716 having a C-shaped or substantiallycylindrical configuration. Further, electrodes 706, 708 may includeproximal insulation 712 (which may or may not extend to proximal portion716) and distal insulation 714. Unlike electrode tube 704, however,distal ends of electrodes 706, 708 may be left free or otherwiseunconnected to one another. That is, electrode tube 702 may not includea distal portion to couple together the distal ends of electrodes 706,708. Instead, the distal ends of electrodes 706, 708 may includegeometric features configured to secure electrode tube 702 to electrodetube 704. For example, in one example, electrodes 706, 708 may includeopposing bends 718, 720, respectively, for frictionally engaging distalportion 732 of electrode tube 704. Bends 718, 720 may be preformed, ormay be formed during assembly of electrode tube 702 into electrode tube704, as described below. In such examples, a distal endface of distalportion 732 may include corresponding notches for receiving andretaining bends 718, 720 therein, as shown in FIG. 6D. Further,electrodes 706, 708 may include a substantially constant cross-sectionalconfiguration along an entire length thereof. Alternatively, thecross-sectional configuration of one or both of electrodes 706, 708 mayvary along a length thereof. For example, a proximal portion ofelectrode 706 may include a substantially circular cross-sectionalconfiguration and a distal portion of electrode 706 may include asubstantially rectangular or planar cross-sectional configuration.

As shown in FIG. 6B, electrode tube 702 may be configured to be receivedwithin electrode tube 704. Accordingly, in some examples, electrode tube702 may be configured to be biased radially outwardly, so that electrodetube 702 may be frictionally retained within electrode tube 702. Assuch, electrode tube 702, and electrodes 706, 708 may include resilientproperties.

With reference now to FIG. 6C, assembly of electrode tube 702 withinelectrode 704 may be facilitated via a coaxial inner support 750.Support 750 may be formed from any suitable material. In one example,support 750 may be formed from a material stiff enough to lendstructural rigidity as described herein. Further, support 750 may definea plurality of grooves 752 for receiving and retaining electrodes 706,708, 722, 724 therein. Further, support 750 may define a longitudinallumen 751 therethrough for receiving, e.g., a pull wire. Support 750 mayprovide structural rigidity to the entire assembly 700 so that bends718, 720 may be formed during assembly. Further, support 750 may beconfigured to maintain a spacing between electrode tube 702 and 704during assembly. This spacing may allow for routing and assembly of theaforementioned thermocouple wires and optional shrink tube covering forstrain relief purposes.

An energy delivery array 800 is shown in FIG. 7 in a collapsedconfiguration. Energy delivery array 800 may extend distally from one ormore elongate members such as, e.g., sheaths, catheters, bronchoscopes,endoscopes, or the like. Energy delivery array 800 may extend from aproximal end 801 toward a distal end 802, and may include a first polarassembly 803 and a second polar assembly 804. Thus, in at least someexamples, energy delivery array 800 may be configured to deliver bipolarenergy (e.g., bipolar RF energy) from one polar assembly to anotherpolar assembly that are insulated from one another. In one example, RFenergy may be transferred from second polar assembly 804 through tissuesof the body (e.g., tissues of the lung) to first polar assembly 803.However, it is also contemplated that RF energy may be transferred fromfirst polar assembly 803 through tissues of the body to second polarassembly 804.

First polar assembly 803 may include a proximal end piece 806 and adistal end piece 808. Proximal and distal end pieces 806 and 808 may beformed of any suitable electrically conductive material, such as, e.g.,metals or alloys including one or more of copper, steel, platinum,plastic materials with a conductive metal insert or coating, or thelike. End pieces 806 and 808 may be formed from substantially the samematerials, or from different materials, if desired. End pieces 806and/or 808 may be substantially elongate, hollow cylindrical members, ormay be formed in another suitable configuration. Proximal end piece 806may be coupled to distal end piece 808 by one or more energy transferelements 810. In the example shown in FIG. 7, two energy transferelements 810 are shown coupling proximal end piece 806 to distal endpiece 808, although other suitable configurations, e.g., one, three, ormore energy transfer elements 810 also may be utilized.

Energy transfer elements 810 may be coupled to proximal and distal endpieces 806 and 808 by any suitable mechanism including, but not limitedto, welding, soldering, machining, adhesives, crimping, laserattachment, or the like. Energy transfer elements 810 may be coupled toany suitable surface of proximal and distal end pieces 806 and 808 suchas, e.g., a longitudinal end surface, an inner radial surface, an outerradial surface, or any other suitable surface. Energy transfer elements810 may be radially spaced from one another relative to a longitudinalaxis 820 of energy delivery array 800. Energy transfer elements 810 maybe formed from any suitable material, such as those used to formproximal and distal end pieces 806 and 808. In some examples, energytransfer elements also may be formed of a shape memory metal or alloy,such as, e.g., nitinol.

Second polar assembly 804 may include a proximal end piece 812 and adistal end piece 814. Proximal and distal end pieces 812 and 814 may beformed of substantially similar materials as proximal and distal endpieces 806 and 808 of first polar assembly 803, or from differentmaterials, if desired. End pieces 812 and/or 814 may be substantiallyelongate, hollow cylindrical members, or may be formed in anothersuitable configuration. Proximal end piece 812 may be coupled to distalend piece 814 by one or more energy transfer elements 816. In theexample shown in FIG. 7, two energy transfer elements 816 are showncoupling proximal end piece 812 to distal end piece 814, although othersuitable configurations, e.g., one, three, or more energy transferelements 816 also may be utilized. Proximal end piece 812 of secondpolar assembly 804 may be disposed proximally of proximal end piece 806of first polar assembly 803. Distal end piece 814 of second polarassembly 804 may be disposed distally of distal end piece 808 of firstpolar assembly 803. Thus, end pieces 806 and 808 of first polar assembly803 may be disposed between (along longitudinal axis 820) end pieces 812and 814 of second polar assembly 804.

Energy transfer elements 816 may be radially spaced from one anotherrelative to longitudinal axis 820 of energy delivery array 800, and maybe substantially similar to energy transfer elements 810 of first polarassembly 803, or may include a different configuration, if desired.Further, energy transfer elements 816 may be coupled to proximal anddistal end pieces 812 and 814 in a substantially similar manner asenergy transfer elements are coupled to proximal and distal end pieces806 and 808 in first polar assembly 803.

In one example, however, energy transfer elements 816 may be received byrecesses 818 formed in an outer radial surface of distal end piece 814.Similar to energy transfer elements 816, recesses 818 may be radiallyspaced from one another about longitudinal axis 820. In some examples,it is contemplated that proximal end piece 806, distal end piece 808,and proximal end piece 812 may alternatively or additionally includerecesses formed in their respective outer radial surfaces for receivingan end of a given energy transfer element 810 or 816.

Energy transfer elements 810 may alternate with energy transfer elements816 radially about longitudinal axis 820. Further, in some examples,energy transfer elements 810 may be disposed about a first circumferenceof energy delivery array 800, while energy transfer elements 816 may bedisposed about a second circumference of energy delivery array 800. Inone example, the first circumference may be spaced further from acentral longitudinal axis (e.g., longitudinal axis 820) or radial centerof electrode delivery array 800 than the second circumference. Thus,energy transfer elements 810 may be disposed further from a centrallongitudinal axis or radial center of energy delivery array 800 thanenergy transfer elements 816. However, it is contemplated that in somealternative examples, that energy transfer elements 816 may be disposedfurther from a central longitudinal axis (e.g., longitudinal axis 820)or radial center of energy delivery array 800 than energy transferelements 810.

Each of energy transfer elements 810 and 816 may include an exposedactive region 826 that is configured to deliver RF energy to bodytissues. Active region 826 may be defined proximally and distally alongenergy transfer elements 810 and 816 by a proximal insulated region 828and a distal insulated region 830. Along proximal insulated region 828and distal insulated region 830, energy transfer elements 810 and 816may be unable to deliver energy to bodily tissues. Proximal and distalinsulated regions 828 and 830 may be formed from any suitable material,such as, e.g., a heat shrink sleeve, a dielectric polymeric coating, orother suitable material which may function as an insulator. Proximal anddistal insulated regions may be coupled to energy transfer elements 810and 816 by any suitable mechanism, such as, e.g., heat shrinking or thelike.

The one or more active regions 826 of energy transfer elements 810and/or 816 may include one or more temperature sensing elements 832. Inone example, each active region 826 may include two temperature sensingelements 832 (e.g., thermocouples or the like), and each temperaturesensing element 832 may include a lead 834 that is coupled to acontroller and/or power source (not shown) of energy delivery array 800.Leads 834 may be routed proximally through proximal insulated regions828, or in any other suitable configuration.

An activation element 836 may extend from proximal end 801 toward distalend 802 of energy delivery array 800. Activation element 836 may besubstantially similar to activation element 104 described with referenceto FIG. 5, and may be coupled to any suitable actuator. Activationelement 836 may include expansion supporters (not shown) that aresubstantially similar to expansion supporters 106, 107 to maintainspacing between energy transfer elements 810 and 816. Activation element836 may be coupled to distal end piece 814 in any suitable manner tofacilitate movement of energy delivery array 800 between the collapsedconfiguration shown in FIG. 7 to a radially expanded configuration (notshown, but substantially similar to the expanded configuration ofelectrode cage 102 shown in FIG. 5). In some examples, activationelement 836 may be pulled proximally, thereby moving distal end pieces814 and 808 proximally to cause buckling and outward radial expansion ofeach of energy transfer elements 810 and 816. Thus, the longitudinalmovement of activation element 836 may cause the radial expansion andcontraction of energy delivery array 800.

Energy delivery array 800 may be configured to operate in a bipolarconfiguration, although other suitable configurations are alsocontemplated. First and second polar assemblies 803 and 804 may beinsulated from one another by insulation elements 822 and 824.Insulation element 822 may be disposed between proximal end piece 806 offirst polar assembly 803 and proximal end piece 812 of second polarassembly 804. Insulation element 824 may be disposed between distal endpiece 808 of first polar assembly 803 and distal end piece 814 of secondpolar assembly 804. In some examples, insulation elements 822 and 824may be generally disk shaped with a central aperture (e.g., insulatingelements 822 and 824 may be insulating washers) although other suitableinsulating configurations are also contemplated.

In some examples, activation element 836 may be configured to deliverenergy from a controller and/or power source to distal end piece 814 andenergy transfer elements 816 of second polar assembly 804. It is furthercontemplated that other activation elements (not shown) may also deliverenergy to first polar assembly 802. In some examples, first polarassembly 803 and second polar assembly 804 may be separate poles of anRF circuit each with a different polarity supplied by the power source.In some examples, the polarities of the poles may oscillate at highfrequency. As second polar assembly 804 may be insulated from firstpolar assembly 803, when energy delivery array is disposed within bodilylumens and tissues, RF energy may flow from second polar assembly 804,through bodily tissues, to proximal end piece 806, distal end piece 808,and energy transfer elements 816 of first polar assembly 803, heatingthe bodily tissues surrounding energy delivery array 800. Alternatively,energy may flow from first polar assembly 803, through bodily tissues,to second polar assembly 804.

FIGS. 8-11 depict an exemplary assembly sequence of energy deliveryarray 800. FIG. 8 depicts a partially-assembled first polar assembly803. As shown in FIG. 8, two energy transfer elements 810 may be coupledto proximal end piece 806. Distal end piece 808, which is shownunattached to energy transfer elements 810 in FIG. 8, may be attached toenergy transfer elements 810 by any suitable mechanism described aboveto form first polar assembly 803 as shown in FIG. 9. Energy transferelements 816 (shown already coupled to proximal end piece 812 in FIG.10) may be inserted through a lumen defined by proximal end piece 806toward distal end piece 808 of first polar assembly 803. As shown inFIG. 11, energy transfer elements 816 may be extended distally through alumen of distal end piece 808 to distal end piece 814 of second polarassembly 804. Thus, in some examples, energy transfer elements 816 maybe longer than energy transfer elements 810 to accommodate the assemblyprocess described herein.

The various catheters, electrode arrays, energy delivery arrays, andother devices disclosed in the specification may be coupled to one ormore shafts and/or sheaths having a length in a range from about 0.5feet to about 8.0 feet, or another suitable length. In some examples,the energy delivery arrays and/or baskets may have an expanded basketdiameter in a range from about 1 mm to about 25 mm, or in anothersuitable range. In some examples, the exposed portions of an electrodeleg, e.g., active regions 826, may be about 5 mm in length. In otherexamples, active regions 826 may be in the range from about 1 mm to 50mm in length, or may have another suitable length.

In various examples of the present disclosure, RF energy may be appliedto tissues defining a body lumen (e.g., a lung airway) for a length oftime in the range of about 0.1 seconds to about 600 seconds. In oneexample, a power source may be capable of delivering about 1 to 100watts of RF energy, and may possess continuous flow capability. Thetissues defining a lung airway may be maintained at a temperature thatis lesser than, equal to, or greater than ambient body temperature. Inone example, the tissues may be maintained at at least about 60° C.,between 70° C. to 95° C., and/or between 70° C. to 85° C. The RFpower-level may generally range from about 0-30 W, or another suitablerange. In some examples, the power source may operate at up to a 75° C.setting. In some examples, RF energy may be delivered in discreteactivations of, e.g., 5 to 10 seconds per activation. The frequency ofthe RF energy may be from 300 to 1750 kHz. It should be noted that, inat least some examples, other suitable values for energy delivery times,wattage, airway temperature, RF electrode temperature, and RF frequencyare also contemplated.

Moreover, while specific examples may have been illustrated anddescribed collectively herein, it should be appreciated that anysubsequent arrangement designed to achieve the same or similar purposemay be substituted for the specific examples described and shown herein.This disclosure is intended to cover any and all subsequent adaptationsor variations of the various examples. For example, it is contemplatedthat the above-described exemplary method steps can occur consecutively,simultaneously, or in various order with each other and with other stepsthat could be included. Combinations of the above examples, and otherexamples not specifically described herein, will be apparent to those ofordinary skill in the art upon reviewing the present disclosure.

Other examples of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the examples disclosed herein. It is intended that the specificationand examples be considered as exemplary only, and departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as defined by the following claims.

What is claimed is:
 1. A medical device, comprising: an expandableenergy delivery array reciprocally movable between a first configurationand a second configuration, the expandable energy delivery arraycomprising: a first assembly having a unitary first proximal end piece,a unitary first distal end piece, and a plurality of first energytransfer elements each directly coupled to and extending between theunitary first proximal and unitary first distal end pieces; and a secondassembly having a unitary second proximal end piece, a unitary seconddistal end piece, and a plurality of second energy transfer elementseach directly coupled to and extending between the unitary secondproximal and unitary second distal end pieces, wherein the unitarysecond proximal end piece is proximal to the unitary first proximal endpiece, and a proximalmost portion of the unitary second distal end pieceis distal to a distalmost portion of the unitary first distal end piece,wherein the first and second energy transfer elements circumferentiallyalternate with one another relative to a longitudinal axis of themedical device such that each first energy transfer element iscircumferentially between two second energy transfer elements, and eachsecond energy transfer element is circumferentially between two firstenergy transfer elements; wherein: the first and second assemblies areelectrically insulated from one another; the first and second proximalend pieces are separated by a first insulating element containedlongitudinally between the first and second proximal end pieces; and thefirst and second distal end pieces are longitudinally separated by asecond insulating element contained longitudinally between the first andsecond distal end pieces.
 2. The medical device of claim 1, wherein adistalmost portion of the unitary second proximal end piece is proximalto a proximalmost portion of the unitary first distal end piece, and thefirst insulating element is an insulating washer.
 3. The medical deviceof claim 1, wherein the second insulating element is an insulatingwasher.
 4. The medical device of claim 1, wherein distalmost ends of thesecond energy transfer elements extend through one or more notchesdisposed in an outer radial surface of the unitary second distal endpiece.
 5. The medical device of claim 1, wherein the first energytransfer elements are disposed further from a longitudinal axis of theenergy delivery array than the second energy transfer elements.
 6. Themedical device of claim 1, further including an activation element thatextends from a proximal end of the medical device through the first andsecond assemblies, the activation element being coupled to the unitarysecond distal end piece, wherein longitudinal movement of the activationelement is configured to reciprocally move the energy delivery arraybetween the first and second configurations, wherein the firstconfiguration is a collapsed configuration and the second configurationis a radially expanded configuration, wherein the activation element isconfigured to deliver RF energy to the second assembly.
 7. The medicaldevice of claim 1, wherein each of the first and second energy transferelements includes an active region defined at proximal and distalportions by insulating regions, wherein the active region is configuredto deliver RF energy to body tissues when in contact with the bodytissues, and the insulating regions are not configured to deliver RFenergy to body tissues at any time, and the active region of at leastone first or second energy transfer element includes at least onetemperature sensing element configured to sense a temperature of theactive region or of body tissue.
 8. The medical device of claim 1,wherein the energy delivery array is configured to deliver energy tobody tissues in a bipolar configuration.
 9. A medical device,comprising: an expandable energy delivery array reciprocally movablebetween a first configuration and a second configuration, the expandableenergy delivery array comprising: a plurality of first energy transferelements, a first proximal end piece, and a first distal end piece,wherein each of the plurality of first energy transfer elements iscoupled at a proximal end to the first proximal end piece, and iscoupled at a distal end to the first distal end piece, and the firstproximal end piece and the first distal end piece are hollow cylinders;and a plurality of second energy transfer elements, a second proximalend piece, and a second distal end piece, wherein the plurality of firstenergy transfer elements alternate with the plurality of second energytransfer elements circumferentially about a longitudinal axis of theenergy delivery array such that each first energy transfer element iscircumferentially between two second energy transfer elements, and eachsecond energy transfer element is circumferentially between two firstenergy transfer elements, wherein radially outermost portions of each ofthe plurality of first energy transfer elements are spaced further fromthe longitudinal axis of the energy delivery array than radiallyoutermost portions of each of the plurality of second energy transferelements, wherein each of the plurality of second energy transferelements is coupled at a proximal end to the second proximal end piece,and is coupled at a distal end to the second distal end piece, and thesecond proximal end piece and the second distal end piece are hollowcylinders; wherein: the plurality of first energy transfer elements andthe plurality of second energy transfer elements are electricallyinsulated from one another; the first and second proximal end pieces areseparated by a first insulating element contained longitudinally betweenthe first and second proximal end pieces; and the first and seconddistal end pieces are separated by a second insulating element containedlongitudinally between the first and second distal end pieces.
 10. Themedical device of claim 9, further including an activation element thatextends from a proximal end towards a distal end of the medical device,the activation element configured to deliver energy to the plurality ofsecond energy transfer elements.
 11. The medical device of claim 9,wherein each first energy transfer element is circumferentially offsetfrom each other first energy transfer element, and each second energytransfer element is circumferentially offset from each other secondenergy transfer element.
 12. A medical device, comprising: an expandableenergy delivery array reciprocally movable between a first configurationand a second configuration, the expandable energy delivery arraycomprising: a first assembly having a first proximal end piece, a firstdistal end piece, and a plurality of first electrodes extending betweenthe first proximal and first distal end pieces, each of the plurality offirst electrodes being circumferentially offset from each other of theplurality of first electrodes; and a second assembly having a secondproximal end piece, a second distal end piece, and a plurality of secondelectrodes extending between the second proximal and second distal endpieces, each of the plurality of second electrodes beingcircumferentially offset from each other of the plurality of secondelectrodes, wherein a distalmost portion of the second proximal endpiece is proximal to both i) a proximalmost portion of the firstproximal end piece and ii) proximalmost ends of each of the plurality offirst electrodes, and a proximalmost portion of the second distal endpiece is distal to i) a distalmost portion of the first distal end pieceand ii) distalmost ends of each of the plurality of first electrodes,wherein: the first and second assemblies are electrically insulated fromone another; the first and second proximal end pieces are separated by afirst insulating element contained longitudinally between the first andsecond proximal end pieces; the first insulating element directlycontacts a proximally-facing surface of the first proximal end piece anddirectly contacts a distally-facing surface of the second proximal endpiece; the first and second distal end pieces are separated by a secondinsulating element contained longitudinally between the first and seconddistal end pieces; and the second insulating element directly contacts adistally-facing surface of the first distal end piece and directlycontacts a proximally-facing surface of the second distal end piece; andan activation element configured to reciprocally move the expandableenergy delivery array between the first configuration and the secondconfiguration, wherein when the expandable energy delivery array is inthe first configuration, proximal movement of the activation element isconfigured to move both the first and second distal end piecesproximally to cause each of the first electrodes and the secondelectrodes to buckle and expand radially outward.
 13. The medical deviceof claim 12, wherein each first electrode is disposed circumferentiallybetween two second electrodes, and each second electrode is disposedcircumferentially between two first electrodes.
 14. The medical deviceof claim 12, wherein each first electrode is circumferentially adjacentto only second electrodes, and each second electrode iscircumferentially adjacent to only first electrodes.
 15. The medicaldevice of claim 12, wherein each of the first proximal end piece, thesecond proximal end piece, the first distal end piece, and the seconddistal end piece is unitary in construction, each first electrode isdirectly coupled to both the first proximal end piece and the firstdistal end piece, and each second electrode is directly coupled to boththe second proximal end piece and the second distal end piece.
 16. Themedical device of claim 15, wherein each of the first proximal endpiece, the second proximal end piece, the first distal end piece, andthe second distal end piece is a hollow cylinder.
 17. The medical deviceof claim 16, wherein distalmost ends of the second electrodes eachextend through a respective notch disposed in an outer radial surface ofthe second distal end piece.
 18. The medical device of claim 17, whereinproximalmost ends of the second electrodes each extend through arespective notch disposed in an outer radial surface of the secondproximal end piece.